Restoring Type 4 pulley/fan alignment

[raygreenwood]

Both A and B discussed in my "how to".

So we have three parts in the picture/sketch. Lets name them for conversation sake.

1. Hub. The part that has a tapered bore and bolts to the crank

2. The aluminum fan casting that is pinned to the hub

3. The steel pulley ring which is held tight and centered to the aluminum fan ring....only by the four through bolts

Terminology:
Axial: means in line with the centerline of the crankshaft
Radial: means radiating outward perpendicular to the centerline of the crankshaft

I spoke about scenario A....the relationship between the tapered steel hub that bolts to the crankshaft and the aluminum fan casting section. This is where I found a radial "out of round" variation of .003". The steel hub on the crank was measured by itself and does not have this radial issue.....so its in the casting or machining of the aluminum fan casting.

I spoke about scenario B primarily.....because the steel pully ring was out of alignment becasue the through bolts had been loosened.

There is a third possibility of misalignment that we did not address that Steve asked about. That being.....is the machine work on the steel hub that mates to the crank centered.

I have not set up a way to measure that....perfectly.....and I cannot find my rounded micrometer anvil attachment....but from crude measurements....the machine work to the hub appears to be very straight.

Your last question.....will the misalignment of the aluminum fan section not cause the same vibration and problems with the pulley?

No.....Because we are aligning the steel pulley ring.....to the steel crank hub so they are all on the same radial centerline....regardless of the radial position of the cast aluminum fan section.

Its important to visualize.....the steel pulley ring.....is NOT bolted to the cast aluminum fan ring......its CLAMPED to the cast aluminum fan ring by through bolts that are in holes larger in diameter than the bolts. Ray

[furgo]

[Hoody]

And after 3 pages....the rule is do not take your fan apart.

[furgo]

There was one time I had to change tires and I simply looked up the Owner's Manual and got the ones I needed.

I then saw the 180-page tire thread on The Samba and stopped worrying about the length of discussions on the forum.

Everyone has a particular area of interest, and that's fine
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'79 Westy, P22 interior, FI 2.0 l Federal, GE engine (hydraulic lifters)

Decode your M-Plate

[raygreenwood]

[airkooledchris]

you can take it to get balanced.

I didn't take mine apart but still brought it in when I had other things balanced. They said it was already perfect, but they could do it if it hadn't been.

[raygreenwood]

[SGKent]

[69BahamaYellow]

Glad I read this thread. Didn't even think about the pulley ring not being self centering, when it's disassembled / reassembled....

Pulled my fan apart as well to clean/paint, but I'm thinking it will be pretty easy to re-align the pulley ring just by bolting the fan onto the crankshaft (without the fan housing), so you can rotate the whole assembly and use a dial indicator on the pulley ring. I would think you could lightly clamp the 4 bolts and correct the eccentricity by lightly tapping the pulley ring in increments of 1/2 the total indicator reading at a time, then tighten down the 4 bolts to full torque, once you get everything to within a few thousandths.

After I get the fan and pulley ring right, and before I re-assemble my engine, I'm going to bolt the fan, A/C drive pulley, flywheel, and pressure plate to the crankshaft, mark every nut and bolt, and scribe the relationship of the pressure plate to the flywheel, and then take the whole assembly to a shop for a proper 2 plane dynamic balancing.

[f1wanabe]

Read through the thread and have a question. Never removed the fan, but my fan was pretty dirty with relatively loose dirt. It seems to have been sitting in a dusty environment at some point. There was dirt sitting in the inside groove of the pulley, so I cleaned it out. I now have a 2000 rpm vibration. Looked over pictures of fans to see if there was any balancing weight added to the fan itself and came across this picture. My fan also had something like a plastic material inside the channel until I cleaned it! What material was used to balance the fans? I can still see the discolored area where it sat, maybe I could add it back?

[Wildthings]

I think the original balance weights were just steel, but could be wrong. You could certain try adding weights back. I have just used hunks of welding rod and siliconed them in place for testing purposes. Once you get the correct weight in the correct location you can go back and JB Weld them in place.

[SGKent]

Well, when a fan is that way............... time to find another and send that one to Ray so he can take it apart and play with it. I see a 10,532 word post in his and your future.

Bummer of a birthmark Hal

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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[raygreenwood]

[raygreenwood]

Oh....Wildthings....quick note!

I saw your post about the possible captive inner nut on the pivot point bracket.

While I do not recall ever seeing one personally.....if the bracket in my picture originally had one and its now lost....it would totally explain why the hole is so much larger and so uniform.

Since all of my parts are originally 411/412...I will check my range of 411/412 specific books and if see if there is a picture and mention and possibly part #.
of an alternator bracket with a captive nut. Ray

[Wildthings]

[raygreenwood]

[drlong]

Ray. Would you be able to re assemble and align a pulley assembly for me?+
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If it's not broke it must not be a VW

[raygreenwood]

[Abscate]

It’s a coincidence that there are 10.532 pictures in this thread
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.ssS!

[SGKent]